Elsevier

Neuroscience

Volume 166, Issue 1, 10 March 2010, Pages 5-14
Neuroscience

Behavioural Neuroscience
Research Paper
Replacement with GABAergic steroid precursors restores the acute ethanol withdrawal profile in adrenalectomy/gonadectomy mice

https://doi.org/10.1016/j.neuroscience.2009.11.075Get rights and content

Abstract

The neurosteroid allopregnanolone (ALLO) is a progesterone metabolite that is one of a family of neuroactive steroids (NAS) that are potent positive allosteric modulators of γ-aminobutyric acidA (GABAA) receptors. These GABAergic NAS are produced peripherally (in the adrenals and gonads) and centrally in the brain. Peripherally produced NAS modulate some effects of ethanol intoxication (e.g., anxiolytic, antidepressant, and anticonvulsant effects) in rodents. We have found that NAS also may be involved in the rebound neural hyperexcitability following a high ethanol dose. Removal of the adrenals and gonads (ADX/GDX) increased withdrawal severity following 4 g/kg ethanol, as measured by handling-induced convulsions (HICs) in male and female DBA/2J mice. NAS are produced through the metabolism of progesterone (PROG), deoxycorticosterone (DOC), or testosterone, which can be blocked with the administration of finasteride (FIN), a 5α-reductase enzyme inhibitor. The current investigation was undertaken to clarify the step(s) in the biosynthetic NAS pathway that were sufficient to restore the acute ethanol withdrawal profile in ADX/GDX mice to that seen in intact animals. Male and female DBA/2J mice underwent ADX/GDX or SHAM surgery. After recovery, separate groups of animals were administered PROG, DOC, PROG+FIN, DOC+FIN, FIN, ALLO, ganaxalone (a synthetic ALLO derivative), corticosterone, or vehicle. Animals were then administered a 4 g/kg ethanol dose and allowed to undergo withdrawal. HICs were measured for 12 h and again at 24 h. The results indicate that replacement with PROG and DOC restored the withdrawal profile in ADX/GDX animals to SHAM levels, and that this effect was blocked with co-administration of FIN. Administration of FIN alone increased the withdrawal profile in both SHAM and ADX/GDX males. These findings indicate that the increase in acute withdrawal severity after ADX/GDX may be due to the loss of GABAergic NAS, providing insight into the contribution of endogenous GABAergic NAS to ethanol withdrawal severity.

Section snippets

Subjects

Drug naive D2 male and female mice were purchased from Jackson West Laboratories (Davis, CA, USA) and were 8–12 weeks old at the time of experiment. Animals were group housed (four/cage, separated by sex) and were allowed free access to rodent chow (Labdiet 5001 rodent diet; PMI International, Richmond, IN, USA) and water. Mice were maintained on a 12 h (6 am to 6 pm) light/dark cycle in polycarbonate cages (Thorens, Hazleton, PA, USA) in a room kept at 21±2 °C with humidity control. Mice were

Results

A multifactorial repeated measures ANOVA was used in order to determine if FIN administration had suppressed ALLO levels during the withdrawal period. Time was a within subjects factor, while sex and drug administration were between subject factors. There were a significant effects of sex [F(1,107)=12.99, P<0.001; female>male] and drug administration [F(1,107)=49.27, P<0.001; VEH>FIN], and no other interactions. These results confirmed that FIN pretreatment had suppressed ALLO production during

Discussion

Previous work in our laboratory has shown that removing the main peripheral sources of PROG- and DOC-derived NAS increased acute EtOH withdrawal severity in D2 male and female mice (Gililland and Finn, 2007). These studies replicated these results as animals that had undergone ADX/GDX surgery had a more severe withdrawal profile than animals that had undergone a SHAM surgery. Further, the lack of effect of GDX on withdrawal severity in D2 male mice suggested that testosterone-derived NAS had no

Acknowledgments

The work presented was supported by grants from the Department of Veterans Affairs and the NIAAA (AA12439 to DAF and AA10760, Portland Alcohol Research Center component to DAF, and an F31 pre-doctoral training grant to KRK, AA017019).

References (60)

  • M. Holzbauer et al.

    In vivo secretion of 3a-hydroxy-5a-pregnan-20-one, a potent anaesthetic steroid, by the adrenal gland of the rat

    J Steroid Biochem

    (1985)
  • A.M. Hosie et al.

    Conserved site for neurosteroid modulation of GABAA receptors

    Neuropharmacology

    (2009)
  • S.H. Mellon et al.

    Neurosteroids: biochemistry and clinical significance

    Trends Endocrinol Metab

    (2002)
  • M. Mhatre et al.

    Chronic ethanol treatment upregulates the GABA receptor beta subunit expression

    Brain Res Mol Brain Res

    (1994)
  • A.L. Morrow et al.

    Steroid hormone metabolites potentiate GABA receptor-mediated chloride ion flux with nanomolar potency

    Eur J Pharmacol

    (1987)
  • R.W. Olsen et al.

    GABAA receptors: subtypes provide diversity of function and pharmacology

    Neuropharmacology

    (2009)
  • M. Orchinik et al.

    Adrenalectomy selectively regulates GABAA receptor subunit expression in the hippocampus

    Mol Cell Neurosci

    (1994)
  • D.S. Reddy

    Is there a physiological role for the neurosteroid THDOC in stress-sensitive conditions?

    Trends Pharmacol Sci

    (2003)
  • M.T. Reilly et al.

    Acute neuroactive steroid withdrawal in withdrawal seizure-prone and withdrawal seizure-resistant mice

    Pharmacol Biochem Behav

    (2000)
  • A.J. Roberts et al.

    Genetic differences in hypothalamic-pituitary-adrenal axis responsiveness to acute ethanol and acute ethanol withdrawal

    Brain Res

    (1992)
  • R. Rupprecht

    Neuroactive steroids: mechanisms of action and neuropsychopharmacological properties

    Psychoneuroendocrinology

    (2003)
  • S.S. Smith et al.

    Neurosteroid regulation of GABAA receptors: focus on the a4 and d subunits

    Pharmacol Ther

    (2007)
  • N.G. Weiland et al.

    Specific subunit mRNAs of the GABAA receptor are regulated by progesterone in subfields of the hippocampus

    Brain Res Mol Brain Res

    (1995)
  • M. Beers et al.
  • D. Belelli et al.

    The contraceptive agent Provera enhances GABAA receptor-mediated inhibitory neurotransmission in the rat hippocampus: evidence for endogenous neurosteroids?

    J Neurosci

    (2003)
  • D. Belelli et al.

    Neurosteroids: endogenous regulators of the GABAA receptor

    Nat Rev Neurosci

    (2005)
  • W.F. Busby et al.

    Effect of methanol, ethanol, dimethyl sulfoxide, and acetonitrile on in vitro activities of cDNA-expressed human cytochromes P-450

    Drug Metab Dispos

    (1999)
  • R.B. Carter et al.

    Characterization of the anticonvulsant properties of ganaxolone (CCD 1042; 3a-hydroxy-3b-methyl-5a-pregnan-20-one), a selective, high-affinity, steroid modulator of the gamma-aminobutyric acidA receptor

    J Pharmacol Exp Ther

    (1997)
  • G. Chastain

    Alcohol, neurotransmitter systems, and behavior

    J Gen Psychol

    (2006)
  • T.J. Davis et al.

    Alcohol's actions on neuronal nicotinic acetylcholine receptors

    Alcohol Res Health

    (2006)
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